Editing Electric power distribution (section)

==History==
{{further|History of electric power transmission}}
[[File:Brush Company arc light madison square new york 1882.png|thumb|upright|The late 1870s and early 1880s saw the introduction of [[arc lamp|arc-lamp]] lighting used outdoors or in large indoor spaces, such as this [[Brush Electric Company]] system installed in 1880 in [[New York City]].]]

Electric power distribution become necessary only in the 1880s, when electricity started being generated at [[power stations]]. Until then, electricity was usually generated where it was used. The first power-distribution systems installed in European and US cities were used to supply lighting: [[arc lamp|arc lighting]] running on very-high-voltage (around 3,000 V) [[alternating current]] (AC) or [[direct current]] (DC), and [[incandescent lamp|incandescent lighting]] running on low-voltage (100 V) direct current.<ref>Quentin R. Skrabec, The 100 Most Significant Events in American Business: An Encyclopedia, ABC-CLIO – 2012, page 86</ref> Both were supplanting [[gas lighting]] systems, with arc lighting taking over large-area and street lighting, and incandescent lighting replacing gas lights for business and residential users.

The high voltages used in arc lighting allowed a single generating station to supply a string of lights up to {{convert|7|mi|km|adj=off}} long.<ref>{{cite journal|journal=Journal of the Society of Telegraph Engineers|last1=Berly|first1=J.|publisher=Institution of Electrical Engineers|volume=IX|date=1880-03-24|title=Notes on the Jablochkoff System of Electric Lighting|url=https://books.google.com/books?id=lww4AAAAMAAJ&pg=PA143|issue=32|page=143|access-date=2009-01-07}}</ref> And each doubling of voltage would allow a given cable to transmit the same amount of power four times the distance than at the lower voltage (with the same power loss). By contrast, direct-current indoor incandescent lighting systems, such as [[Pearl Street Station|Edison's first power station]], installed in 1882, had difficulty supplying customers more than a mile away because they used a low voltage (110 V) from generation to end use. The low voltage translated to higher current and required thick copper cables for transmission. In practice, Edison's DC generating plants needed to be within about {{convert|1.5|mi|km}} of the farthest customer to avoid even thicker and more expensive conductors.

=== Introduction of the transformer ===
The problem of transmitting electricity over longer distances became a recognized engineering roadblock to electric power distribution, with many less-than-satisfactory solutions tested by lighting companies. But the mid-1880s saw a breakthrough with the development of functional transformers that allowed AC power to be "stepped up" to a much higher voltage for transmission, then dropped down to a lower voltage near the end user. Compared to direct current, AC had much cheaper transmission costs and greater [[economies of scale]] — with large AC generating plants capable of supplying whole cities and regions, which led to the use of AC spreading rapidly.

In the US the competition between direct current and alternating current took a personal turn in the late 1880s in the form of a "[[war of currents]]" when [[Thomas Edison]] started attacking [[George Westinghouse]] and his development of the first US AC transformer systems, highlighting the deaths caused by high-voltage AC systems over the years and claiming any AC system was inherently dangerous.<ref>{{cite book|first1=Webb B.|last1=Garrison|title=Behind the headlines: American history's schemes, scandals, and escapades|url=https://archive.org/details/behindheadlinesa00garr|url-access=registration|publisher=Stackpole Books|year=1983|page=[https://archive.org/details/behindheadlinesa00garr/page/107 107]|isbn=9780811708173}}</ref> Edison's propaganda campaign was short-lived, with his company switching over to AC in 1892.

AC became the dominant form of transmission of power with innovations in  Europe and the US in [[electric motor]] designs, and the development of engineered ''universal systems'' allowing the large number of legacy systems to be connected to large AC grids.<ref name="Thomas Parke Hughes 1930, pages 120-121">{{cite book |last1=Parke Hughes |first1=Thomas |title=Networks of Power: Electrification in Western Society, 1880–1930 |publisher=JHU Press |year=1993 |isbn=9780801846144 |pages=120–121}}</ref><ref name="Raghu Garud 2009, page 249">{{cite book |last1=Garud |first1=Raghu |title=Managing in the Modular Age: Architectures, Networks, and Organizations |last2=Kumaraswamy |first2=Arun |last3=Langlois |first3=Richard |publisher=John Wiley & Sons |year=2009 |isbn=9780631233169 |page=249}}</ref>

In the first half of the 20th century, in many places the [[electric power industry]] was [[vertical integration|vertically integrated]], meaning that one company did generation, transmission, distribution, metering and billing. Starting in the 1970s and 1980s, nations began the process of [[deregulation]] and [[privatization]], leading to [[electricity market]]s. The distribution system would remain regulated, but generation, retail, and sometimes transmission systems were transformed into competitive markets.